In general, a photovoltaic system has merits such as cleanliness and inexhaustibility so that many countries have performed research for the photovoltaic system for a global environmental problem and a measure for energy diversification as a part of development of alternative energies.
In general, according to the photovoltaic system capable of producing energy by using sunlight, a plurality of photovoltaic modules are connected in serial-parallel connection to be connected to a power conversion device. That is, only one photovoltaic module has so low output voltage. Therefore, a plurality of photovoltaic module is connected in series to boost an output voltage, and a plurality of serial connection arrays are connected in parallel to get final power.
However, the photovoltaic module generates heats when producing electric power by using solar energy, and the heats deteriorates electric power generation capability. Therefore, effective heat dissipation is necessary in order to improve efficiency of the photovoltaic system.
Additionally, extra support structures are required in order to install the photovoltaic module at a roof of a house, etc., and the extra support structures are required even to a new-built house. Therefore, a structure of the house and aesthetic features of city are damaged.
Additionally, when the photovoltaic module is installed at a region with limited area such as a region with concentrated buildings and houses, there may be output power deviation between the photovoltaic modules due to a shadow of a building, a housing, a tree, etc., a shadow induced by sun angle, and various contaminant such as fallen leaves. When the photovoltaic modules with deviation are connected in series, final output power is lowered.